This invention relates to an image organizing unit of a laser beam printer, and more particularly, to an image organizing, unit capable of modulating the organization of an oblique line image without improving the receiving power of the printer.
Recently, there has become widespread a so-called laser beam printer in which the charged surface of a photoconductive member is exposed, to form a latent image, to a laser beam modulated on the basis of printing information inputted from, for instance, an external host computer. With the latent image thus formed, a hard-copy is electrophotographically obtained through a toner-image development process, a transferring process, and a fixing process. Particularly, a semi-conductor laser beam printer has been applied in actual use as is compact in size and light in weight.
The laser beam printer has features, in comparison to conventional printers, such as fast printing speed, multiplicity of recording methods, high quality of printed impression, low noise at printing operation, and employability of usual papers, etc. Therefore, needs for the laser beam printer are rapidly increasing, such as for information outputting terminal equipment to be connected to computers or the like which are required for so-called Office Automation.
In the laser beam printer, generally, quality of a printed impression depends upon a, resolving power of the printer, and this resolving power depends upon the spectral sensitivity of a photoconductive member, the spot diameter of the beam, the beam intensity, and the scanning speed of the photoconductive member.
In case the printer is connected to a computer or the like as its outputting equipment, the number of characters to be used is usually not more than the number of character codes defined by ASCII (American Standard Code for Information Interchange), and therefore the printing quality, i.e., the resolving power does not matter so much. In this connection, it is enough to set the resolving power to be 120 DPI (Dots Per Inch). Thus, usually a frame-size and a character-size of each character data stored in a character generator are composed respectively to be 120 DPI and 1/6 inch.
However, there exists a problem that in case the frame-size and the character-size of each character data are determined as above, an oblique line of the character has an awful impression. For example, the character pattern of "A" comprises 10-dots (width).times.20-dots (height), as illustrated in FIG. 3, in case the characters are to be printed at a rate of 12 characters per inch and 6 lines per inch. Thus, oblique lines of the character "A" are not represented smoothly.